Method of and machine for making gauges and other articles



April 22 1924. 1,491,104

w. E. HOKE METHOD OF AND MACHINE FOR MAKING GAUGES AND OTHER ARTICLES Filed July 8, 1919 Patented Apr. 22, 1924.

- UNITED (STATES PATENT OFFICE.

WILLIAM E. EOKE, or s'rf'LoUIs, MISSOURI, ASSIGNOR T0 PRATT & WHITNEY cou- PAN-Y, OF NEW YORK, N. Y., A coRroRA'rIoNor NEW JERSEY.

METHOD OF AND MACHINE FOR MAKING GAUGES AND OTHER ARTICLES.

Application filed July 8,

To all whom it may concern:

Be it known that I, WILLIAM E. HoKE, a citizen of the United States, residing at St. Louis, Missouri, have invented certain new and useful Improvements in Methods of and Machines for Making Gauges and Other Articles, of which the following is a specification.

This invention relates toa method ofthe method may be practiced.

In accordance with the present invention the lapping is effected between vertically disposed laps instead of between horizontal- 1y disposed laps as set forth in the aforesaid application. For certain classes of work, particularly for lapping very short or thin blocks, it is preferable to use vertical laps, as the action upon both end sur faces is then identical. With horizontal laps there is a tendency for the heavier and coarser particles of emery to accumulate on the lower lap surface. The lapping therefore takes place more. rapidly on the bottom and the bottom surfaces of the blocks are scratched more deeply. These deeper I method.

scratches not only give the bottom surface an appearance different from that of the top surface, but they are objectionable, as they have a peening effect which tends to spread or expand the metal adjacent the surface. When the blocks are thin this greater spreading or expanding tendency atone surface may be sufficient to actually warp the blocks to a slight extent.

In the accompanying drawing I have illustrated in diagrammatic form a machine embodying the mechanical features of the invention and adapted for practicing the I have. also presented further diagrams by which the method will be ex? plained in detail. It will be understood that 1919. ,Serial No. 309,452.

the drawings are for illustrative purposes only and are not'tobe construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

Of the drawing:

Fig. 1 is a vertical sectional view of a machine adapted for carrying out my improved method.

Fig. 2 is an end view of the principal parts of the machine shown in Fig. 1.

Figs. 3 and 4; are diagrammatic views I further illustrating the method.

The blocks to be lapped are first formed with the desired shape and with a little more than the desired length, by any usual or preferred means. When they are to be.

used as gauges the blocks are hardened and otherwise suitably treated, but these preliminary steps constitute n0 part'o-f the present invention. After the blocks have been thus formed and treated, they are then subjected to a lapping operation or a series of lapping operations and are otherwise acted upon, in the manner to be described.

Referring to Figs. 1 and 2 of the drawings, it will be seen that the machine includes two laps 1 and 2 of similar size and preferably annular inform, having their adjacent faces 3 and 4 made as nearly plane as possible in accordance with any method for producing plane surfaces. The adjacent surfaces of the two laps are suitably prepared and are charged with an abrasive such as fine emery. The character of the laps and of the abrasive may be varied as required. A number of similar blocks A-A are placed between the two laps 1 and 2, these blocks being preferably arranged in a circular series, as shown. For holding the blocks in proper relationship and for other purposes, as will be presently de- 13. As before stated, the blocks A--A, to gethcr with the spider 5, are placed between the laps, the blocks being engaged by the surfaces 3 and 4. The two laps ,1 and 2 are forced together by any suitable means, such I for instance as springs 14, 14 and 15, 15,

interposed respectively between the lap 1 and the bracket plate 11 and between the lap 2 and the bracket plate 12. The two laps are supported on the bearing studs in such a way that they can freely adjust themselves as to parallelism in accordance with the lengths of the several blocks.

In order to effect lapping relative movement is caused between the spider 5 and the laps. Preferably the spider is moved and the laps are held against any considerable movement. As illustrated, one of the bearing studs. as for instance 10, is hollow and a rotatable shaft 16' extends through it.

This shaft is adapted to be driven by a pulley 16. At. its inner end the shaft 16 carries a crank 17 which enters a central aperture in the spider 5. When the crank is turned the spider is given a bodily circular movement. It will be seen that the spider is free to turn about the crank pin 17 and the resistance offered to the movement of the blocks is such that the spider is automatically turned slowly, thus being given a planetary or precessional movement. At the same time the blocks themselves roll somewhat within the aperture 6, thus turning slowly about individual axes. The lapping movement is continued preferably until all of the blocks have been lapped and until the laps engage them equally.

Then the lapping movement is stopped and one of the laps is removed,thus leaving the blocks exposed. As illustrated, I provide for the removal of the lap 1, the corresponding bracket plate 11 being slidably mounted on the base 13. As shown in the drawing, the bracket plate is held by bolts 18 entering T-slots 19. Certain blocks are then transferred in such a way as to distribute any errors or variations. in the respective lengths. It may be assumed that, with a group of blocks of slightly varying lengths, those at one part of the group will average longer than those at another part. Following this assumption it will be seen that the transferring must be such that the longer and shorterblocks will be commingled. In order that the longer and shorter blocks may be uniformly distributed, the transferring is preferably eflected symmetrically. If the blocks are arranged in a circular series, it is to be expected that the lengths of those at one side will have a greater average-than the lengths of those at the other side. Inasmuch as the surfaces of both laps are flat, the result is that some one or two of the blocks at one side will have a maximum length and some one or the average. The transferring of the blocks to distribute the errors and equalize the lengths is preferably done by moving alter nate blocks or alternate groups of blocksto positions diametrically opposite. This places the longer blocks between the shorter ones.

For practicing the method in the preferred manner,- the number of blocks in any one circular series, such as a to p. as shown in Fig. 3, should be a multiple of four and should be at least eight. By way of example I have shown sixteen blocks, but it will be understood that any desired multiple of four may be used. If it be assumed for instance that the blocks at one side of a diametral line m-w have lengths greater than the average and that the blocks at the other side'of the line have lengths less than the average, then it will be seen that after the diametral transposition of alternate blocks the longer and shorter blocks will, in the main, be alternately arranged as shown in Fig. 4. The operator has no means of determining the position of the diametral dividing line Zr-m and no means of determining which .is the side of maximum length and which the side of minimum length, but it is not necessary for him to do so. It gvill be observed that inasmuch as the alternate blocks throughout the entire series are transposed, the required alternate arrangement oflonger and shorter block is secured irrespective of the position of the dividing line.

The blocks having been transferred as described the lap 1 is restored to position and the lapping operation is repeated. Obviously the laps will at first engage only the longerblocks, thus reducing their lengths- The lapping operation is continued preferably until the laps again engage all of the .blocks. .Obviously the blocks are more nearly uniform in length than before but there may still be some variation. Therefore alternate blocks are again transferred, as before described, and the blocks are again lapped. These operations are repeated alternately in succession for a number of times, and the final result is that all of the blocks have exactly the same length and have their end surfaces exactly flat and parallel. The manner of moving or transferring the blocks may be varied, particularly in the ways set forth in my aforesaid application.

It will be seen that by arranging the laps vertically and efi'eoting lapping as herein a desired predetermined amount. If considerable additional lapping is uired to secure the desired uniform lengt it may be preferable to continue the transferring of the blocks from time to time to avoid possible variation. The blocks may be measured in any desired way to ascertain when the redetermined lengths have been reached. E se may be made of the method set forth in my aforesaid application, but this method constitutes no art of mypresent invention and need not e here described.

What I claim is:

1. The method of reducing a number of similar blocksto produce parallel fiat end faces and identical lengths, which consists in arranging the several blocks between two opposed vertical flat laps, applying pressure to force the laps together, permitting one of the laps to adjust itself with respect to the other in accordance with the lengths of the blocks, efiecting relative bodily movement between the blocks and the laps in a circular path to effect lapping, causing) relative rotary movement between the locks and the laps about an axis centrally located with respect to the blocks, and causing the blocks to simultaneously turn about individual axes perpendicular to the laps.

2. The method of reducing a number of similar blocks to faces and identica lengths, which consists in arranging the several blocks between two opposed vertical flat laps, applying pressure to force the laps together, permitting one of the lapsto adjust itself with respect to the other in accordance with the lengths of the blocks, efl'ectin relative movement between the blocks and the laps repeating the lap produce parallel flat end to effect lapping, transferring some of the blocks to distribute variations in length, and I ing and transferring o erations alternate y until identical lengths are obtained.

3. A lapping machine including in combination, two opposed vertically disposed fiat laps, means or holding a number of similar blocks in position between the laps, devices for applying pressure to the laps to force them togetherfthe said laps being free to relatively adjust themselves in accordance with the lengths of the blocks, and mechanism for bodily moving .the block holding means in a circular path with respect to the laps whereby lapping is effected, the said mechanism permitting the block holding means to freely turn about a central axis as it is moved circularly.

4. A lapping machine including in com bination, two opposed vertically disposed laps, means for holding a number of similar articles in position between the laps means for applying pressure to the laps to force them together, one of said la s being free to adjustitself as to par elism relative to the other lap in accordance with the length of the articles, and means to cause relative movement of the articles across the entire surface of each of the laps whereby lapping is efl'ected. 5. A lapping machine including in combination, two opposed vertically disposed laps, means for holding a number of similar articles in position between the laps, means for applying pressure to the laps to force them together, said laps being relatively adjustable as to parallelism to adjust themeselves in accordance with the length of the articles, and means to cause relative movement of the articles across the entire surface of each of the laps whereby lapping is effected.

In testimony whereof, I hereto afiix my signature.

WILLIAM E. HOKE. 

